Pneumatic tool.



c. B". RICHARDS. PNEUMATIC ToqL.

No. 6%,033. Patented Jan. 1, l90l.

(Applicgtion filed Dec. 6 1899.) (No Model.) v 3 sham-sheet No. 665,033.Patented' Jan. I, "19m.

C. B. RICHARDS.

PNEUMATIC TOOL.

(Application flied Dec. 6, 1899.) (No Model.) 3 Sheets-Shgt 3.

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UNiTED STATES LATENT Creme.

CHARLES E. RICHARDS, OF CLEVELAND, OIIIO, ASSIGNOR TO THE CLEVE- LANDPNEUMATIO TOOLOOMPANY, OF SAME PLACE.

PNEUMATIC TOOL.

SPECIFICATION forming part of Letters Patent No. 665,033, dated January1, 19012 Application filed December 6, 1899. Serial No. 739,410. (Nomodel.)

State of Ohio, have invented certain new and 4 useful Improvements inPneumatic Tools, of which the following is a specification, theprinciple of the invention being herein explained and the best mode inwhich I have contemplated applying that principle, so as to distinguishit from other inventions.

The annexed drawings and the following description set forth in detailone mechanical form embodying the invention, such detail constructionbeing but one of various mechanical forms in which the principle of theinvention may be used.

In said annexed drawings, Figure I represents an axial section of myimproved pneumatic tool, showing the plunger and valve in theirpositions at the end of the back stroke of the plunger immediatelybefore the valve is shifted for the operative stroke; Fig. II, an axialsection of the tool, showing the plunger at the end of its operativestroke and before the valve is shifted; Fig. III, an axial section in aplane at right angles to the plane of the former sections; Fig. IV, atransverse section on the line IVIV in Fig. I and looking forward; Fig.V, a transverse section on the line V V in Fig. I; Fig. VI, a transversesection on the line VI VI in Fig. II; Fig. VII, a transverse section onthe line VII VII in Fig. II; Figs. VIII and IX, respectively a rear viewand a front view of the cap, and Fig. X a rear end view of the barrel.

The hammer has a barrel 1 formed with an annular shoulder 2 at its innerend. A cylindrical valve-casing- 3 has a bearing with its closed endagainst the shouldered end of the barrel, and a cap 4 bears against theother end of the valve-casing, closing said end. A sleeve 5 has aninternal flange b and is slipped over the barrel to have said'flangeengage the shoulder of the barrel, and said sleeve has an externalscrew-thread which is engaged by an internally-screw-threaded sleeve 7,from which a pistol-grip handle 8 extends. The barrel has a bore 9,wl1ich forms the plungercylinder and terminates in a smaller bore at theend of the barrel, into which bore a toolsocket 10 is forced. The shank33 of the working tool fits in said socket. The plunger-cylinder isformed with an enlargement 11 in its outer end at the inner end of thetool-socket. A plunger 12 fits to reciprocate in the cylinder and hastwo pistons 13, a reduced portion 14 between said pistons, and a reducednose 15 at its outer end, which nose engages and strikes the end of thetool-shank. The actuating fluid, which is usually compressed air, entersthe handle at the end of the same and passes through a channel 16 insaid handle. The air-tube 17 is screwed into the open end of avalvecasing 18, which is cylindrical, and is secured transverselythrough the end of the handle, in which is formed an annular chamber 19,communicating with the air-channel in the handle, and a longer annularchamber 20, opening through the handle and closed by a screw-plug 21,through which the valve-casing is screwed. Immediately at the end of thescrew-plug the valve-casing has an annular series of perforations 22,forming a port communicating with the larger chamber, and a partition 23is formed inthe valve-casing directly above such port. An annular seriesof perforations 24, forming a port, is formed through the valve-casing.at the inner end of the large annular chamber. The interior of thevalveoasing communicates with the small annular chamber and theair-channel through an annular series of perforations 25, forming aport. A valve 26, having a cup-shaped piston 27 at its inner end and apacking-piston 28 near its outer end, slides in the valve-casing and isforced outward by a spring 29, fitted in the cup-shaped piston andbearing against the partition in the valve-casing. The end of thevalve-stem 30 projects through the side of the handle, and a lug 31 upona latch 32 bears against it. Said latch is fulcrumed at one end upon theinner, side of the handle, so that the latch may be pressed by the handholding the handle to force the valve in and be released to cause thevalve to slide out by the action of the spring of the latter. Whenhandle. When the latch is pressed and the valve forced in, said latterport is uncovered and the air may flow through it and the interior ofthe valve casing out through the other port into the air-channel. Asmall hole 34 is preferably formed through the cupshaped piston for thepurpose of equalizing the pressure upon both sides of the valve.

The above described valve mechanism forms the throttle-valve mechanismof the hammer, by means of which the supply of air to the hammer iscontrolled. The air-channel 16. opens into the closed end of the sleeveof the handle and enters a recess 35 in the rear face ofthe cap 4. Achannel 36 extends through the cap, near the periphery of the same andfrom the recess, and said channel registers with and is continued byachannel 37 in the valve-casing and, further, by a channel 38 in the sideof the barrel. Two ports 39 and 40 open from said channel into theplunger-cylinder at about equal distances from and near the middle ofthe same. The actuating-air is continually admitted in said channel whenthe throttle-valveis open. The valve-casing has a cylindricalvalve-chamber 41, closed at its forward end by a wall of the casing andat its rear end by the cap. A valve 42, having a central piston 43 andend pistons 44 and 45, slides in said valve-chamber. Two ports 46 and 47open from the airinlet channel into the valve-chamber in such mannerthat one of the channels between the central piston and the end pistonsmay alternately register with one of said ports as the valve isreciprocated and arrives at the extremes of its play. The valve-casingis surrounded by an exhaust-chamber 48, formed by the handle-sleeve andthe flanged sleeve, and one or more ports 49 open from saidexhaust-chamber through the handle-sleeve. Exhaust-ports 50 areformedthrough the valve-casing from the two extremes of the valve-chainberinto the exhaust-chamber, and said exhaust-ports are of acomparatively small diameter and area and are permanently open to theexhaust-chamber, so that air may be exhausted from the ends of thevalve-chamber when the valve therein is forced toward the ends, whileadmission of live air into the ends of the valve-chamber will shift thevalve, with only a small quantity of air leaking out through theexhaustport. Two large ex-. hanst-ports 51 and 52 are formed from nearthe middle of the valve-chamber through the casing and into theexhaust-chamber. Said ports are so arranged that the rear exhaustport 51will register with the rear valve-channel when the forward live-air port47 registers with the forward valve-channel at the forward extreme ofthe valve throw and the forward exhaust-port 52 will register with theforward valve-channel when the rear live-air port 46 registers with therear valve-channel at the rear extreme of the valve throw. A

channel 53 extends from the enlargement at the forward end of theplunger cylinder through the side of-the barrel and through the side ofthe valve-casing, and said channel has a port 54, which registers withthe forward exhaust-port 52, and a port 55,which registers with theforward live-air port 47. A recess 56 is formed in the rear end of theplungercylinder and communicates with a channel 57 through the side ofthe valvecasing. Said channel has two ports 58 and 5.), of which theforward, 59, registers with the rear exhaust-port 51 and the rear, 58,registers with the rearlive-air port 46. Achannel 60 extends from theforward end of the valve-chamber to a port in the plunger-cylinderregistering with the rear inlet-port 39. A channel 61 extends from therear of the valve-chain her, where a recess 62 is formed in the forwardface of the cap 4, to a port in the plunger-cylinder, which registerswith the forward inletport 40. A shallow channel 63 is formed in theforward face of the closed end of the valve-casing to form a smallpermanent inlet from the live-air-inlet channel to the rear end of theplunger-cylinder. The rear edge of the flanged coupling-sleeve 5 isformed with ratchet-teeth 64, which are engaged by a pawl 65, sliding inthe handle-sleeve, to prevent the parts from turning and unscrewingduring the operation of the hammer. Said pawl has a spring 66, forcingit into engagement with the ratchet-teeth, and a pin 67 ex.- tends fromthe pawl through an L-shaped slot 68 in the handle-sleeve, so that thepawl may be locked in its disengaged position by turning the pin intothe lateral notch of the slot.

In practice the air-inlet of the handle is connected to a source of airunder pressure by means of a hose or similar flexible or movableconnection. When the latch is pressed inward by the hand holding thegrip of the handle, air is admitted to the hammer. When the tool isnotinserted in the hammer, the plunger is in the position shown in Fig.III, and the port which conducts the live air to shift the valve fromthe forward to the rear position is closed and the live air let into theouter end of the plungencylinder will escape through the tool-socket, sothat the hammer will remain inoperative until the tool is inserted, eventhough the air is admitted into the hammer. When the tool is inserted,the plunger is pushed back and the outer end of the plunger-cylinder isclosed to allow the air passing down to said end to return the plunger.The valve is in the position illustrated in Fig. I and the plunger inthe position shown in Fig. II. The live air will pass from theinlet-channel through the forward live-air port and valve-channel to theforward port of the channel leading to the outer end of theplunger-cylinder, forcing the plunger back into the position in Fig. I.The back stroke of the plunger will force the air behind the plungerthrough the recess 56 and channel 57 to the forward port 59 ofthe same,whence itwill pass through the IIO valve-channel and registeringexhaust-port into the exhaust-chamber and thence out of the hammer. Atthe end of the back stroke the plunger will be cushioned by the live airentering the rear end of the plunger-cylinder through thepermanently-open shallow channel 63. When the plunger arrives at the endof the back stroke, communication is made between the rear inlet-port inthe cylinder and the. registering port of the valve-shifting channel 60,so that air may pass through said channel into the forward end of thevalve chamber, shifting the valve back into the p0 sition shown in Fig.II. This will place the rear live-air port in communication through therear valve-channel with the port 58 and channel 57, leading to the rearend of the plunger-cylinder, admitting the live air behind the plungerto drive the same forward. The air in front of the plunger escapesthrough the channel leading from the forward end of the plunger-cylinderand through the rear port of said channel through the valve-channel andout through the forward exhaustport of the valve-chamber. When theplunger reaches the end of its forward stroke, the valve is againshifted by communication formed between the plunger-pistons from theforward live-air inlet-port in the plunger-cylinder to thevalve-shifting channel-port registering with said inlet-port, thusadmitting live air to the rear of the valve and forcing the latterforward. While the valve is shifting the exhaust from the forward end ismomentarily shut off. The enlargement of the plunger-cylinder at thatend will, however, admit of the small volume of confined air escaping tothe sides of the plunger, so as not to cushion the forward blow of theplunger upon the tool-shank in the tool-socket.

ward throw of the valve, the back jar of the plunger striking the toolis partly or entirely neutralized by the forward jar caused by the throwof the valve, so that a very slight jar only is felt by the hand holdingthe hammer. This is a great advantage in this kind of a tool, as theoperators of this kind of toolfrequently suffer considerably from thesevere jar to the hand and arm during the operation of the tool to suchextent as to render the continued operation of the tool for anyconsiderable space of time impossible. The air exhausts from the ends ofthe valvechamber through the small exhaust-ports in the ends of thesame, which ports have so much less area than the inlet-ports into theends of the chamber that they Will permit the live air to shift thevalve with a comparatively small escape of said air through the ports,while they will allow the exhaust-air to escape when the valve is forcedover by the pressure of live air on the opposite side of the valve.

When it is desired to take the hammer apart for inspection or repair,thepawl is withdrawn As the forward blow of the plunger is immediatelyfollowed by the forfrom the ratchet-teeth of the-coupling-sleeve v andthe handle is unscrewed from said sleeve. The sleeve may then be pusheddown upon the barrel and the valve-casing and cap may be removed, givingfree access to the valve and the plunger.

There are no small'parts in this hammer to be injured by the hard usageto which a tool of this character is subjected and to consequentlyimpair the usefulness of the ham mer; All parts are easily constructedand are easily accessible. The valve-actuating mechanism is very muchsimplified by having the small permanently-open exhaust-ports in theends of the valve-chamber, as the number of ports and channels andcorresponding controlling mechanism is reduced, and the Waste of airpistons and conducting the air directly to the channels leading to therespective ends of the valve-chamber. The construction of the hammer isalso simplified by using the same channel at the forward and rear end ofthe plu ngercylinder for inlet and exhaust, so that the drilling ofchannels and complication of valvecasing ports and of the valvestructure is avoided. The pawl-and-ratchet device upon the handle-sleeveand coupling-sleeve will prevent said parts from unscrewing by the jarof the operating-hammer, and the pawl may be easily withdrawn and heldwhenever it is desired to take the hammer apart. The throttle-valve iseasily controlled, as the grip of the hand holding the handle-gripduring operation of the hammer will pull on the latch and keep the valveopen, and release of such grip will immediately release the latch andshut off the air. From practical use of the hammer it has been proventhat hardly any jar is experienced to the hand holding it dur ingoperation, but that the upward jar from the plunger striking the tool isneutralized by the immediately-following downward jar of the solid valvebeing thrown forward toward the forward end of the valve-chamber. Thecushioning effect to the forward stroke of the plunger of the slightquantity of air confined in the outer end of the plunger-cylinder by thechange ot the valve and consequent cutolf of the exhaust from that endis removed by the enlargement of the outer end of the cylinder,whichallows the plunger to laterally displace the air and to thus strike thetool with its full force Other modes of applying the principle of myinvention may be employed for the mode herein explained. Change maytherefore be -IIO made as regards the mechanism thus disclosed,providedthe principles of construction set forth respectively in the followingclaims are employed.

I therefore particularly point out and distinctly claim as myinvention 1. In a pneumatic tool, the combination with a barrel formedwith a plunger-cylinder and a valve-casing arranged in axial alinementwith and at the inner end of said barrel, of a plunger reciprocating inthe barrel, a distributing-valve reciprocating in the valvecasing, andmeans for causing the valve to be thrown forward immediately followingthe forward throw of the plunger, thereby neutralizing the back jar fromthe plunger striking the tool, substantially as set forth.

2. In a pneumatic tool, the combination with a barrel formed with aplunger-cylinder and a valve-casing arranged in axial alinement with andat the inner end of said barrel, of a plunger reciprocating in thebarrel and a distributing-valve reciprocating in the valvecasing andactuated by the actuating fluid, said plunger being constructed tocontrol the actuating fluid to throw said valve in such manner that theforward throw of the plunger admits the actuating fluid to the valve tothrow the latter foward, thereby neutralizing the back jar from theplunger striking the tool, substantially as set forth.

3. In a pneumatic tool, the combination with a barrel formed with aplunger-cylinder, and a valve casing arranged in axial alinement withand at the inner end of said barrel, two inlets for the actuating fluidand opening in the plunger-cylinder, and two channels opening in theplunger-cylinder at points registering with the inlets and extending oneto each end of the chamber in the valve-casing, of a valve in saidchamber constructed to control the actuating fluid for theplunger-cylinder and to be reciprocated by alternate admission of theactuating fluid to the ends of the valve-chamber, and a plungerreciprocating in the plunger-cylinder and actuated by the actuatingfluid distributed therein by said valve and constructed with a passagewhich alternately connects one inlet in the cylinder with one passage tothe valve-chamber and which connects the passage to the rear end of saidchamber at the forward end of the throw of the plunger, therebyneutralizing the back jar from the plunger striking thetool,substantially as set forth.

4. In a pneumatic tool, the combination with a barrel formed with aplunger-cylinder, a valve-casing having its chamber in axial alinementwith and at the inner end of said barrel, an inlet channel for theactuating fluid and having inlets into the cylinder at points near themiddle of the same, a channel leading from a port registering with theforward of said inlets to the rearend of the valvechamber and a channelleading from a port registering with the rear of said inlets to theforward end of the valve-chamber, of a distributing-valve in saidchamber and con structed to distribute the actuating fluid to the endsof the plunger-cylinder and to be shifted by the alternate admission ofthe actuating fluid to the ends of the chamber, and a plunger in thecylinder and formed with a passage which alternately connects the inletsof said cylinder with the registering ports, substantially as set forth.

5. In a pneumatic tool, the combination with a barrel formed with aplunger-cylinder and a valve-casing arranged in axial alinement with andat the inner end of said barrel, of a plunger reciprocating in thebarrel, a solid distributing-valve reciprocating in the valvecasing, andmeans for causing the valve to be thrown forward immediately followingthe forward throw of the plunger, thereby neutralizing the back jar fromthe plunger striking the tool, substantially as set forth.

6. In a pneumatic tool, the combination with a barrel formed with aplunger-cylinder and a valve-casing arranged in axial alinement with andat the inner end of said barrel, of a plunger reciprocating in thebarrel and a solid distributing-valve reciprocating in the valve-casingand actuated by the actuating fluid, said plunger being constructed tocontrol the actuating fluid to throw said valve in such manner that theforward throw of the plunger admits the actuating fluid to the valve tothrow the latter forward, thereby neutralizing the back jar from theplunger striking the tool, substantially as set forth.

7. In a pneumatic tool, the combination with a barrel formed with aplunger-cylinder, and a valve-casing arranged in axial alinement withand at the inner end of said barrel, two inlets for the actuating fluidand opening in the plunger-cylinder, and two channels opening in theplunger-cylinder at points registering with the inlets and extending oneto each end of the chamber in the valve-casing, of a solid valve in saidchamber constructed to control the-actuating fluid for theplunger-cylinder and to be reciprocated by alternate admission of theactuating fluid to the ends of the valve-chamber, and a plungerreciprocating in the plunger-cylinder and actuated by the actuatingfluid distributed therein by said valve and constructed with a passagewhich alternately connects one inlet in the cylinder with one passage tothe valve-chamber and which connects the passage to the rear end of saidchamber at the forward end of the throw of the plunger, therebyneutralizing the back jar from the plunger striking the tool,substantially as set forth.

8. In a pneumatic tool, the combination with a barrel formed with aplunger-cylinder, a valve-casing having its chamber in axial alinementwith and at the inner end of said barrel, an inlet-channel for theactuating fluid and having inlets into the cylinder at points near themiddle of the same, a channel leading from a port registering with theforward of said inlets to the rear end of the valve-chamber and achannel leading from a port registering with the rear of said inlets tothe forward end of the valve-chamber,of a solid distributing-valve insaid chamber and constructed to distribute the actuating fluid to theends of the plunger-cylinder and to be shifted by the alternateadmission of the ac.- tuating fluid to the ends of the chamber, and aplunger in the cylinder and formed with a passage which alternatelyconnects the inlets of said cylinder with the registering ports,substantially as set forth.

9. In a pneumatic tool, the combination of a plunger-cylinder having atool-socket in its outer end and an air-port at the inner end of saidsocket and provided with liveair ports and ports registering with thesame, air-actuated valve mechanism for controlling the supply to theends of the cylinder and having the valve-shifting air-channelscommunicating with the ports registering with the live-air ports in thecylinder, and a plunger in said cylinder and formed with a chan' nelwhich alternately connects the registering ports at the ends of theoperative and back stroke and with a piston which closes all of saidports when the plunger arrives at the end of its unobstructed forwardstroke, substantially as set forth.

10. In a pneumatic tool, the combination of a plungercylinder,air-actuated valve mechanism controlling the air supply and exhaust forthe same, air-channels communicating with the actuating part of saidvalve mechanism, a plunger reciprocating in the cylinder and controllingsaid channels, and a tool inserted in the end of the plunger-cylinder tobe acted upon by the plunger, said tool projecting into the cylinder soas to limit the throw of the plunger to cause the latter to control theair-channels for actuating the valve and so as to cause the plunger topass beyond such limit to close said channels When the tool is removed,substantially as set forth. 4

11. In a pneumatic tool, the combination with the plunger, the toolacted upon by said plunger, and the distributing-valve controlling themovement of the plunger, of means controlled by said tool for stoppingthe operation of said valve when the tool is removed, substantially asset forth.

12. In a pneumatic tool, thecombination with the plunger, the tool actedupon by said plunger, and the distributing-valve controlling themovement of the plunger, of means controlled by said tool for stoppingthe operation of the valve when the tool is removed and for againcausing the valve to resume its operation when the tool is againreplaced in operative position, substantially as set forth.

13. In a pneumatic tool, the combination with the plunger, the valvecontrolling and controlled by the movement of said plunger, and the toolhaving its shank receiving the blow of the plunger at the end of itsforward stroke and limiting such stroke, of means controlled by theposition of the plunger for antomatically stopping the action of thevalve when the tool is removed and the plunger passes beyond its normallimit, substantially as set forth.

14. In a pneumatic tool, the combination with the plunger, the valvecontrolling said plunger, and ports for admitting pressure to actuatesaid valve, of means controlled by the position of the plunger forcontrolling the pressure through said ports to the valve duringthenormal limits of the stroke of the plunger and for cutting off suchpressure when s uch normal 1i mits are exceeded,substantially as setforth.

15. In a pneumatic tool, the combination of a plunger-cylinder, aplunger reciprocating in said cylinder, a valve-chamberformed with twolive-air-inlet ports and two exhaustports and having two portsregistering respectively with an inlet and an outlet port andcommunicating with the inner end of the plunger-cylinder and two portsregistering respectively with the other inlet and exhaust ports andcommunicating with the outer end of the plunger-cylinder, and a valvereciprocating in the valve-chamber and formed with two passages whichalternately connect a liveair-inlet port and its registering port and anexhaust-port and its registering port,substantially as set forth.

16. In a pneumatic tool, the combination of a plunger-cylinder formedwith a port at its rear end and a longitudinal channel in its side andopening at the forward end of the cylinder, a valve-casing formed with acylindrical valve-chamber having two exhaustports at its middle'and twolive-air inlets, one at each side of said exhaust-ports, and formed witha channel in its side having ports into thechamloer respectivelyregistering with the rear inlet-port and with the rear exhaust-port andcommunicating with the rear port of the cylinder and with a channel inits side havin g ports into-the chamber registering respectively withthe forward inlet-port and with the forward exhaust-port andcommunicating with the channel leading to the forward end of theplunger-cylinder, and a valve in the chamber having three pistonsforming two channels which' may alternately register with an inlet-portand an exhaust-port and having means for shifting it, substantially asset forth. 7

17. In a pneumatic tool, the combination of a barrel formed with aplunger-cylinder and with a channel 53 and a port 56 and with a channel38 having ports 39 and 40 and with channels 60 and 61 having portsrespectively registering with said former ports, a valvecasing. having acylindrical valve-chamber and formed with exhaust-ports 51 and 52 and alive-air channel 37 connected to channel 38 and having inlet-ports 46and i? and formed with a channel having ports 54 and 55 andcommunicating with channel 53 and formed with a channel having ports 58and 59 and communicating with port 56 and with channels communicatingwith channels 60 and 61, a three-piston valve 42 in said chamber, and atwo-piston plunger 12 in the plunger-cylinder, substantially as setforth.

18. In a pneumatic tool, the combination of a pistol-grip handle formedwith an air-channel having an annular chamber at the end of the handleand with a lower chamber alined with said latter chamber, a cylindricalvalvecasing having means for connecting the airsupply at one end andinserted through said chambers and formed with a partition and a portbelow said partition and a port above said partition and bothcommunicating with said lower chamber and formed with a portcommunicating with the an nular chamber,a valve in the valve-casinghaving a piston sliding over the port above the partition and a pistonpermanently above the port in the annular chamber, a spring between thepartition and the lower piston, and a pivoted latch upon the handleengaging the valve, substantially as set forth.

19. In a pneumatic tool, the combination of a pistol-grip handle, avalve-casing substantially transverse in the end of said handle, asupply-pipe enteringthe end of said casing, a valve in said casing andcontrolling the passage of air through said casing and handle, and alatch upon the inner side of the handle and engaging the valve to movethe same, substantially as set forth.

20. In a pneumatic tool, the combination with a plunger-cylinderprovided with air inlet and exhaust at its rear end and with a smallduct at said end for permanent admission of live air, of a plungerreciprocating in said cylinder, and means for returning said plunger toand against the air-cushion provided through said permanent airsupplyduct, substantially as set forth.

21. In a pneu matic tool, the combination of a distributingvalve-chamber formed with a small permanently-open exhaust-port and alarger livc-air-inlet port at each end, means for alternately admit-tinglive air to said latter ports, and a piston-\ 'alve reciprocatingin saidchamber, substantially as set forth.

22. In a pneumatic tool, the combination of a plunger-cylinder having aninlet and exhaust port at each end and means for dis tributing the airto and from said ends and formed with a permanently-open live-air-inletport of small area at the inner end of its bore, and a plungerreciprocating in said cylinder and cushioned at its back stroke by theair admitted through said lastmentioned port, substantially as setforth.

In testimony that I claim the foregoing to be my invention I havehereunto set my hand this 1st day of November, A. D. 1899.

CHARLES E. RICHARDS.

Witnesses:

WM. SECHER, K. F. WINDING.

